In wireless communication, a terminal can transmit data by using a random access process. Using a universal mobile telecommunications system (UMTS) as an example, in a random access process, after a user equipment (UE) that acts as a terminal sends an access signature by using a physical random access channel (PRACH), the user equipment parses an acquisition indicator channel (AICH) at a corresponding time point to obtain a random access result.
Currently, in the UMTS system, if the user equipment receives a positive feedback (i.e. ACK) sent by using the AICH, the user equipment can send data of only one transmission time interval (TTI) on a resource obtained by means of contention.
As shown in FIG. 1, a preamble is generated by using a signature, and the signature is the access signature that is selected by the user equipment when the user equipment initiates the random access process on the PRACH. A message part is the data that is actually sent by the user equipment after the user equipment obtains the ACK from the AICH. A length of the TTI may be 10 ms or 20 ms.
After random access, the user equipment can send data of only one TTI. Due to a limited amount of data, if the user equipment needs to send a relatively large data packet, the user equipment needs to perform multiple random access processes to transmit data of multiple TTIs. In this way, a transmission delay of the data packet is increased.
In conclusion, currently, in a random access process, if a terminal needs to transmit a relatively large data packet, a transmission delay is relatively long.